The invention relates to a device for mounting an annular body, such as the inner ring or outer ring of a bearing, on a mating member when the linear expansion coefficient of the annular body is different from that of the mating member.
Conventionally, a paper on a structure for mounting a bearing such as a rolling bearing onto its mating member when the linear expansion coefficient of the bearing is different from that of the mating member is disclosed on pages 407 to 415 of "Lubrication Engineering" (July 1981).
As shown in FIG. 1, this rolling bearing includes an inner ring 2 mounted on a shaft 1, an outer ring 3 mounted on a not shown journal box, and caged cylindrical rollers 5 interposed between the inner ring 2 and the outer ring 3. The shaft 1 is made from a steel, and the inner ring 2 a ceramic. Both axial side end surfaces of the inner ring 2 are tapered so that the width of the inner ring 2 grows larger toward the outer periphery, and clearance-fitted onto the shaft 1. These side end surfaces of the inner ring 2 are clamped between a pair of steel spacers 4 that are close-fitted onto the shaft 1, and it is so designed that no excessive load is applied to the bearing by relative sliding between the inner ring 2 and the spacers 4 on these side end surfaces when the shaft 1 and the spacers 4 expand thermally.
In the above-mentioned rolling bearing, the load applied to the bearing is transmitted to the spacers 4 while amplified by the wedge action of these side end surfaces of the inner ring 2. As a result, the contact surface pressure over these side end surfaces is increased so much that they are worn, damaged, or even broken with the load reaching its upper limit. This disadvantageously limits the allowable maximum
Further, when assembling the inner ring 2 and the spacers onto the shaft 1, relative slip occurs between the inner ring 2 that is clearance-fitted and the spacers 4 that are close-fitted, and this imposes difficulty in making a correct alignment. Thus, certain skill is required for the assembling work, which is a disadvantage from the viewpoint of operability.
Still further, that the side end surfaces of the inner ring 2 are tapered imposes technical difficulty in ensuring a required dimensional accuracy when machining the inner ring 2, and from this arises an additional disadvantage of elevated manufacturing cost.